In Paris recently I noticed an extraordinary phenomenon unfolding around the Eiffel Tower during a casual afternoon stroll. The sans-papiers—as the undocumented migrants are known in local parlance—vended touristy souvenirs around the Champ de Mars, Place du Trocadéro, and the Palais de Chaillot. They often played hide-and-seek games with the police to avoid detection. Struggling migrants from Africa—or more specifically from countries such as the Republic of Congo, Côte d'Ivoire, Chad, Mali, Senegal, Eritrea, and Niger—these vendors live a shadow life in Paris and survive in a particular type of parallel underground economy of the city's tourism industry. Curiously, they sell mostly one product: miniature replicas of the Eiffel Tower. Their surreptitious economic footprint wraps around Gustave Eiffel's soaring tower, built in 1889 to commemorate the centennial of the French Revolution.